Controlling apparatus



April 11, 1933. E, T. JoHNssoN GONTROLLING APPARATUS Filed May 28, 19312 Sheets-Sheet l April 11, 1933; E. T. JoHNssoN CONTROLLING APPARATUS 2Sheets-Skireet 2 Filed May 28, 1931 Patented Apr. 11, 1933 UNITED STATESEMIL T. JOHNSSON, F CHICAGO, ILLINOIS CONTROLLING APPARATUS Applicationled May 28, 1931.

This invention relates to controlling apparatus for controllingpressure, heat, temperature, or the like, and is particularly intendedfor use in connection'with apparatus requiring very close control and isdesigned to 0perate on a low differential of pressure or temperature.However, certain features of the invention may be adapted for generaluse other than for such particular purposes. Devices of this kind areadapted for use in connection withchemical processes, control of thetemperature of rooms, for refrigerators or cooling apparatus and forother purposes which will be apparent from a description of the same.

The objects of the invention are to provide an improved controllingapparatus of the character indicated; to provide a controlling apparatuswhich will be particularly sensitive and which will be eiective inproviding for close control of pressure temperature or the like; toprovide an improved electric switch with novel means for actuating thesame; to provide an electric switch having a floating contact adapted tocoact with iiXed contacts; to provide a switch having a movable memberhaving a substantially rectangular movement; to provide a switch havinga movable contact coacting withl fined contacts; to provide a pluralityof making and breaking points; to provide differential resistance ortension for certain operating parts; and to provide such novel features,adjustments and advantages as will appear from the followingdescription.

In the accompanying drawings illustrating this invention;

,Figure l is a vertical sectional view with the switch shown in openposit-ion and taken substantially on the line 1-1 of Figure 2;

Figure 2 is a sectional view taken on the line 2 2 of Figure 1;

Figure .3 is a sectional view taken on the line 3-3 of Figure 1;

Serial No. 540,709.

Figure 4 is a cross section taken on the line 4--4 of Figure l;

Figure 5 is a cross section taken on the line 5-5 of Figure 1; and

Figures 6, 7 8, and 9 are diagrammatic 50 views illustrating theoperation of the controller. I

The operating parts are preferably mounted in a boX or casing 10 whichfor convenience may have a vacuum or pressure chamber 11 65 secureddirectly thereto by means of bolts 12. A bellows or expansible member 13is arranged in the pressure chamber and has a disc 14 to which isattached a threaded lug 15 which is engaged by the threaded stem on' anadjustable point or thrust member 16. The point or thrust member coactswith the controlling switch but any other suitable pressure actuatedmeans may be used for this purpose. 55

The point 17 of the pressure member 16 engages with a toggle arm'18which is pivoted at 19 to a bracket 20 in the casing l0. The free end ofthe arm 18 coacts wlth a second toggle arm 2l whichis pivoted to aswinging bracket or support 22. Tension springs 23 are secured to theswinging bracket or support 22 and the pivot pin 19 and tend to resistthe upward movement of the toggle arms. The tension on the springslwhich increases as the springs are stretched, is compensated by thetoggle action as the toggle members move upwardly so that a variableresistance is provided at the point 17. The bellows may be of springtype or have a380 spring coact therewith and the action of the toggle inconnection with the springs 23 serves to compensate for the increase ordecrease in tension due to the action or movement of the bellows. f 85 Amovable bearing or roller 24 rests on the upper face of the arm 18 andis pivoted to an adjusting screw 25 which extends out through the sideof the box and is engaged by a nut 26 which is rotatably mounted in theside of the box so that it cannot move longitudinally. As the nut 26 isturned, the roller or bearing 24 will move along the surface of the arm18. This roller also engagesa second arm 27 which is pivoted at 28 inbrackets 29. It will be seen that as the roller 24 is moved inwardly oroutwardly, the leverage is varied Y so that greater or less force isneeded to swing lever 34 is swung. A spring 48 is secured at 49 tooneside of vthe frame 38 andits upper end'projects inwardly to engagewith the back of the lever 34, as shown in Figure 1. The pressure of thearm 27 against a relatively fixed resistance.

The lever 27 is provided with a knife edge or bearing 30which rests onthe upper surface .thereof and which has 'a tang 31 that engages with ahole 32 in the top of the lever. The knife edge engages with notches orbearings 33 in the sides ofa swinging bracket or bell crank lever 34which is substantially U-shaped in cross section. Thev `lower arms 35 ofthis lever are provided with holes or bearings 36 for engaging with aknife edged fulcrum 37v which Vis rigidly secured to one side of asub-frame 38 which is mounted in the box 10.A f j Tension springs 39-are connected at one end Itoears 40on the arms 35 and .at the oppositeend to ears 41 on the upper end Vof an overthrow orA toggle arm 42 which1s bent atl its lower end to provide a socket or bearingf43 which ispivoted on a lip or projection 44 iwhichf extends Ainwardly from theside of the` sub-frame 38. The .upperearms ofthe `lever 34 are providedwith bearings 45 for .receiving projections on a substantially H- shapedplate lor arm y46, the yopposite end of kwhich engages with the arm42-and is provided Ywith a tang 47v thatts Vfreely ina hole in saidplate to hold the parts together. This overthrow or toggle arrangementis also for the purpose ofproviding a substantially uniform tension orpull on` the springs as the this spring against the lever 34 may beadjusted by means fof `an-adjusting screw 50 which engages with athreaded holein the 1 side of the box 10 and which is provided with yalock nut V51.

' Ay switch actuating element or tongue 52 is also pivoted on the knifeedge or bearing e 30. This tongue-or member has twoside bars 53 withnotches .for engagementr withY the Vends of the bearing 30, these barsbeing connected by integrally formed cross pieces 54 and 55a H `Abifurcated swinging Varm-ortappet/V 56 is ,pivoted in notches 57 in theupper arms of the lever 34 and extends downwardly, the lower end beingprovided with projections 58 and .'59 which are spaced apart and whichtake overfand are adapted. to engage at times with the sides of thecross piece 55. .A spring 60 is connected at one end with the lower endtangs or .projections which engage with n holes 66 in the arms 61, theseholes being somewhat larger than the tangs to permit thenecessary'movement. From this descripe tion, it' willY be seen that thecontact 62 is substantially a floating Contact.

The pivot or pin 64 carries avsleeve 67 of insulating material whichfits between twol branches at the endv of a spring 'Contact or switchmember 68 which is preferably formed integrally with a channel shapedplate 69 which ts in a groove-70 in a block of insulating material. 71mounted inthe box 10.

`The plate 69 also vhas lanother integrally formed resilientswitchmemberor contact 72 which 1s best seen in Figure 3. -A- main switchcontact7 3 lits in the channel 69, these parts being ield together inany suitable way., 'and being provided withfa terminal or binding screw74. Another contact plate or Schannel 75 isv mounted in agroove 76 inthe block 71 and is provided .on the lower side with a yielding contact77 which proj ectsoutwardly and is substantially of the same shape asthe Contact 72. i The channel or terminal plate 75 also has anothercontact 78 which is adapt- Y ed to be engaged at times by the contact68. A main contact or switch plate 7 9is secured in the channel or plate75, these parts being provided with a terminal or binding screw `80v TheoperationV ofthe device may be best runderstood from Figurel taken inconnection with Figures 6 to 9 inclusive. Figure 6 illustrates theposition of the parts as shown .in Figure 1, at which time the switch isopen and the pressure or temperature controlled element in normal orretracted position. As soon as sufficient pressure is exerted in thechamber 11`the point 17 is forced upwardly against the lever 18and tendsto'swing this lever on the pivot 19 against the tension of the spring23. lAls the spring is stretched, itsresistance is increasedbut Athis iscompensated forby the toggle arrangement'of the arms 18 and 21 so lthata variable resistt ance is provided for by this springto, compensate forthe action ofthe bellows. The lever Y18 also Vtends to swin-gthe leverV27 through the medium of the adjustable fulcrum or connection 24whichserves to increase or decrease the leverage or advantage of the lever 18with respect. to the lever 27.

The knife edge or bearing 30 on the lever Vil 27 pushes up on the bellcrank lever or swinging bracket 34 and tends to swing it on the fulcrumor pivot 37 against the tension of the springs 39. The brace or link 46at the same time pushes the top of the arm 42.to the left therebyswinging the upper end over the pivot or dead center 44 which tends tomake the tension uniform during the swinging movement of the bellcranklever 34.

As the upper arms of the bell crank lever 34 moveto the left they carrythe pivot 57 beyond the spring 60, as shown in Figure 7. As soon as thepivot 57 passes the dead center it pulls the lower end of the swingingarm and striking member 56 to the right as shown in Figure 7 until theprojection 58 strikes the cross piece on the switch actuating element ortongue 52. This movement permits the lower end of the spring to movepast the tongue 52 thereby swinging the top of the tongue to the rightor to the position shown in Figure 8. This gives a snap action or quickmake or closure for the switch contact member 62. The striking of theprojection 58 on the tongue tends to make the action more positive andto insure the proper actuation of the switch.

rThe actuation of the switch will presently be described but the switchremains closed as long as the pressure in the chamber 11 is suflicientto hold the lever 18 and connected parts in the operative position justdescribed. As soon as the pressure decreases the point 17 lowers and thetendency is to return the various levers and parts to normal position.As soon as the lever 27 moves downwardly, the pivot 57 of the swingingarm 56 again moves to the right until it passes the center line of thespring 60 at which time the spring tends to pull the lower end of thearm 56 to the left or until the projection 59 strikes the swingingtongue 52 which prevents further free movement. This however, causes thelower end of the spring to pass the tongue and to pull the upper end ofthe tongue to the yleft or to initial position, as shown in Figure 6,with the contact 62 resting against a suitable stop or abutment 81 onthe lblock 71.

While such swinging movements are taking place it will also be notedthat the lowering of the pivot 33 permits a corresponding downwardmovement of the contact 62 before it is swung out of closed position.The effect of this is such that the contact 62 moves through asubstantially rectangular path or orbit. In other words, starting frominitial position it first slides up along the abutment 8l, then swingsto the right until it strikes the `main contacts 73 and 79, then movesdown across the face of these contacts and then swings back toitsinitial position.

fhen the swinging tongue 52 moves upwardly it carries the roller orinsulatedv pin 67 up so that the forked end of the switch member 68 iscarried up and the end of the member isso shaped that when the sleeve 67moves toward switch closing position, the contact 68 engages with thefixed contact 78 just before the contact 62 closes against the maincontacts 73 and 79. The closing of this auxiliary switch tends toprevent any arcing between the main switch contacts.

When the switch is opened the arms of the contact 62 slide down over thefaces of the main contacts 73 and 79 and press againstV the auxiliaryspring contacts 72 and 77 which project for some distance beyond themain contacts. The arms of the contact 62 are thus pressed against theyielding or auxiliary contacts until after they are disengaged from themain fixed contacts and the final opening action is the slipping of thearms off from these yielding contacts so that the final break occursbetween the moving contact and these yielding auxiliary contacts whichprevents arcing between the main contact members. It will also beunderstood that the spring contact 68 is disengaged from the contact 78before this final movement occurs. Due to the tripping action of theswitch actuating mechanism, the movement of the branches of the contact62 off from the spring contacts 72 and 77 is exceedingly rapid orinstantaneous so that there' is little possibility of objectionablearcing at these points when the circuit is broken. It will of course beunderstood that the terminals or binding posts 74 and 80 are connectedin any suitable circuit which is to be controlled by the switch.

The amount of pressure required for operating the switch, or thesensitivity of the same may be regulated by the adjusting screw 50 whichcoacts with the spring 48 for adjusting the resistance or variation inpressure required for swinging the bell crank lever 34. The drawingsshow the contacts so arranged that the switch moves to on position on adecrease of pressure in the chamber 11, but it is obvious that thecontacts may be so mounted that the switch will move to on position byan increase in the pressure in chamber 11.

From this description it will be apparent that my controlling device maybe utilized for different purposes and it will also be noted thatmodifications may be made in order to adapt it for different conditionsand some of the features may be utilized without incorporating theentire mechanism and therefore I do not wish to be limited to the lexactstructure shown and described except as specified in the followingclaims in which I claim.

1. In an apparatus of the character set forth, the combination of anactuating mem` ber having a bearing thereon, a bell crank lever engagingwith said bearing and a ful- `crum adjacent thereto, a spring tending to'swing the bell crank lever around on its' fulcrum, a vibrating tonguepivoted on said bearing, a swinging lever pivoted to the bell cranklever and having spaced apart tappets adapted to engage with thevibrating tongue, a spring connecting the upper end of the vibratingtongue with the lower end of the swinging lever and means for limitingthe swinging movement of the upper end of the vibrating tongue, thearrangement being such that when the bearing is raised it will swing thebell crank lever and cause the last named spring to swing the swinginglever and to cooperatev therewith to yswing the yvibrating tongue.

2. A device as per claim 1in which one end of the first named spring isattached to a support which moves therewith so that'the rotative forceagainstthe lever will be substantially uniform as the lever is swung.

- 3. In a device of the character set forth, the. combination of a bellcrank lever having a fulcrum at approximately the center yof the lowerlpart thereof', a `bearing engaging with theV lever at one side of thefulcrum and adapted to actuate the lever, a spring connected with thelever at-the opposite vside of the fulcrum, a swinging arm pivotedadjacent to the lever kand connected at oneend with the spring, a linkconnecting the upper end of the arm with the upper portion of the lever,a vibrating element pivoted adjacent the lower end of the bell cranklever and movable therewith, a swinging arm pivoted to the upper portionof the bell crank lever and having projections adapted to .engage withopposite ysides of the vibrating element when the lever is swung, aspring connecting the .lower end of the swinging lever with the upperyportion of the vibrating element, and means for limiting the swingingmovement of the upper end of the vibrating element, the arrangementbeing such that when the bearing is raised the bell crank lever will beswung on its pivot and the last named spring and the swinging lever willcoac-t to swing the vibrating element in one direction, and when thebearing is lowered, said spring and lever will swing the element in theoppositedirection. f

A device as per claim 3 having an adjustable spring mounted adjacent tothe bell crank lever and tending to resist the move- .ment of the bellcrank lever 1n one direction.

tongue whereby the free end of the vibrating tongue will have areciprocatory and vibratory movement. f

6. The combination ofA a main levermeans for operating said lever, a`secondary lever pivoted to said main lever, a vibrating tongueloperatively connected with the main lever and adapted to movelongitudinally when the lever vis swung, a spring connected with saidsecondary ylever and with said'tongue, said levers beingso arrangedthatamovement of the main lever will swing the pivot of the secondary leverand cause the secondary lever to be tripped by said spring and strikethe vibrating tongue and also topermit the spring to swing said tonguewhereby the free end of the tongue will have a compound movement.

- 7. In a controlling apparatus, the combination ofan electric switchhaving a closing member adapted to move through a limited path, anactuating lever carrying said closing member, a swinging bracket, anwarmpivoted to the swinging bracket and adapted to engage with the-actuating lever to swing the same, a springbetween theactuating leverand the swinging arm for moving the lever when the pivot thereof passesthe Idead center, yielding means 'tending to hold the bracket innormalposition, a lever pivoted adjacent to the bracket, a bearing onsaid lever supporting the actuating lever and engaging with the bracket,asecond lever pivoted adjacent to the last named lever, -a rollerarranged between the last named levers, a screw :for adjusting saidroller, ay spring coacting `with the last `named lever, and meansadapted Vto coact with thelast named lever to actuate the same.

8.- The combination of a bell crank lever member, means for actuatingsaid member to swing it on its fulcrum, a vibrating tonguememberoperatively connected to said bell Ycrank levermember and adaptedto move vlongitudinally when th-e bell crank lever `member is swung, asecondary lever pivotally connectedto one of said first named members,

and a spring having one end connected t-o the free end of the Secondarylever,and the `other end connected to the other of said first namedmembers, said parts `being arranged so that the movement of the bellcrank lever member will.causethesecondary lever to be swung and trippedby the spring which in turn will cause the vibrating tongue t-o swing.

9. Thecombinationof a main lever, means for swinging said lever in onedirection, means Jr`or swinging the'lever in the opposite direction, asecondary lever pivoted to sai-d Vmain4 lever, a vibrating tongueswingmgly connected with the main lever and adapted to km-ovelongitudinally when the main lever swung, an'4 electric contact on saidtongue ladapted to' coact with another contact, a

spring connected Vwith the secondary lever and said tongue, saidleversbeing so arranged that a movement of the main lever will swing thepivots of the secondary lever which will be tripped by the spring, whichin turn will vibrate the vibrating tongue whereby the free end of thevibrating tongue will have a reeiprooatory and vibrating movement, thepath of movement of the connection between said spring and secondarylever being located in a zone intermediate the pivotal axis of said mainlever and the path of movement of the pivotal axis of said secondarylever.

EMIL T. JOHNSSON.

